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Exposure and auxiliary variable sampling probabilities based on chronic obstructive pulmonary disease and asthma at baseline in the Lung Health Study cohort.
| COPD–Free | ||
|---|---|---|
|
|
||
| Asthma | Yes | No |
| Yes | 17/17 = 1 | 97/97 = 1 |
| No | 343/924 = 0.37 | 343/3175 = 0.11 |
|
| ||
| Severe COPD | ||
|
|
||
| Asthma | Yes | No |
|
| ||
| Yes | 23/23 = 1 | 91/91 = 1 |
| No | 343/502 = 0.68 | 343/3597 = 0.095 |
